The engine downsizing trend is in full-force throughout the automotive world, and no market segment is immune. Even the traditionally big-inch full-size truck segment got shook up with the announcement of an available 2.7-liter EcoBoost V-6 engine. Although explicitly performance-related vehicles have not been affected to the same extent as mainstream vehicles, they are not immune. AutoExpress is reporting that the 2015 C63 AMG will get a major engine downsizing from its current 6.2 naturally-aspirated liters, to a 4.0-liter twin-turbocharged V-8.The German brands have long since abandoned the practice of decklid numerology being a literal description of engine displacement, and although the C63 appellation will probably continue, it will be applied to a significantly smaller engine. AutoExpress estimates the output of the downsized AMG bent-eight to be between 450 to 500 horsepower with the available Performance Pack.In terms of specifics on the new engine, AMG product chief Tobias Moers only coyly said, "You are now familiar with our 2.0-liter four-cylinder engine? Well, you can imagine what happens when you put two of those together." Reading between-the-lines, the new AMG V-8 could have a flat-plane crank, which makes for optimal exhaust-pulse phasing for turbochargers, but results in a flat exhaust note that sounds similar to a four-cylinder. AMG V-8s, including the recent 5.5-liter twin-turbo, have always had a burbly exhaust note that comes with a cross-plane crank. But if such a configuration makes for optimal performance, we could learn to love the new sound of AMG performance.Source: AutoExpress

AutoExpress quoted head of AMG Tobias Moers recently which in a way confirms what we already knew. The upcoming W205 C63 AMG which is expected to debut late this year will have twin turbo V8 power courtesy of a direct injected 4.0 liter V8 with 450-500 horsepower. The quote from Moers is as follows, "You are now familiar with our 2.0-litre four-cylinder engine? Well you can imagine what happens when you put two of those together."

One should not expect double the output of say a CLA45 AMG as that would put the C63 at 710 horsepower. One should expect the C63 to hit 710 horsepower with tuning relatively easily though unless Mercedes really undersizes the stock turbos. Regardless, the W205 C63 AMG is going to have plenty of tuning potential.

If they don't call it the C55 I will be a bit upset. I can see why the new 63s are called as such, given that German companies have a tendency for referring to the engine in terms of absolute power levels, not pure displacement. E23 745i, etc. But calling the new one a C63 would be a bit silly, and I really hope they don't do that. Or maybe C60. That's got an interesting ring to it.

Either way, I'm really excited for this engine. Its going to be a monster right out of the box, and if it takes extra boost like the S63, 700+ crank hp should be a walk in the park. That plus weight loss and RWD should make this thing a serious worry for the M3/4 and whatever Audi is planning on at the moment.

Oh I see what you mean with the M157. Yeah the reasoning by Mercedes was that whole people would think it would be a step back and since the hp and torque was up they decided to keep the numbers.

The thing is with the C and E no longer sharing the motor it's going to get pretty odd now.

Precisely.............that's kinda what I've noticed with the numbers. At some point MB decided to let the 63 be more an indication of the power levels than actual displacement.

Of course, to that some might say what about the supercharged 5.5s from the early/mid 2000s E55s, for instance, that the 63 replaced? It had similar numbers. Again, the thought process evolved.

And while we're on the topic of the M156 and AMG 63s' nomenclature, uh, short of gas mileage numbers that don't live up to today's CAFE standards.............was it really that bad to put 'em in all AMGs? Considering it can upgraded to M159 SLS levels, that is, around 620 hp/480 lb.ft.? Bring it on, dawg.

Also, considering that it was International Performance Engine of the Year in 2009 and 2010, only to be replaced by a Ferrari V8 (2011) and the Berlinetta's V12 (2012)? Answer me that.

I say we stop being dumbasses, start drilling for more of our own frickin crude, drop gas prices back to January 2009 levels ($1.80 - $1.90) or less, and bring back the damn M156 and M159. Not that $3.50-4.00 a gallon ever scared me; spent too many years in Europe, so wake me when it hits $10/gallon. (About $5 after most of my fellow Americans will $#@!in & moanin, thereby dropping prices right back down. Hah!)

But I digress. Back to the M156.

It is the world's and my favorite DTM engine for the street, but way more nasty @ 6.2 liters vs. 4.0 limited displacement in the DTM. Can't wait to drive it later today. I mean, come on.............370 lb.-ft. @ 2000 rpm? Just over 400 @ 3000? Yo, it idles @ 900-950!! Nasty beast.

Last, but not least, on the new 4.0? My preference is clearly the 6.3, but if the 4.0 (or 5.5 for that matter) sounds right.....like "propa" AMG V8, pulls way way harder, yet can extract even more power and gets better gas mileage?

Precisely.............that's kinda what I've noticed with the numbers. At some point MB decided to let the 63 be more an indication of the power levels than actual displacement.

Of course, to that some might say what about the supercharged 5.5s from the early/mid 2000s E55s, for instance, that the 63 replaced? It had similar numbers. Again, the thought process evolved.

And while we're on the topic of the M156 and AMG 63s' nomenclature, uh, short of gas mileage numbers that don't live up to today's CAFE standards.............was it really that bad to put 'em in all AMGs? Considering it can upgraded to M159 SLS levels, that is, around 620 hp/480 lb.ft.? Bring it on, dawg.

Also, considering that it was International Performance Engine of the Year in 2009 and 2010, only to be replaced by a Ferrari V8 (2011) and the Berlinetta's V12 (2012)? Answer me that.

I say we stop being dumbasses, start drilling for more of our own frickin crude, drop gas prices back to January 2009 levels ($1.80 - $1.90) or less, and bring back the damn M156 and M159. Not that $3.50-4.00 a gallon ever scared me; spent too many years in Europe, so wake me when it hits $10/gallon. (About $5 after most of my fellow Americans will $#@!in & moanin, thereby dropping prices right back down. Hah!)

But I digress. Back to the M156.

It is the world's and my favorite DTM engine for the street, but way more nasty @ 6.2 liters vs. 4.0 limited displacement in the DTM. Can't wait to drive it later today. I mean, come on.............370 lb.-ft. @ 2000 rpm? Just over 400 @ 3000? Yo, it idles @ 900-950!! Nasty beast.

Last, but not least, on the new 4.0? My preference is clearly the 6.3, but if the 4.0 (or 5.5 for that matter) sounds right.....like "propa" AMG V8, pulls way way harder, yet can extract even more power and gets better gas mileage?

I'll get over it. Might be crazy, but I ain't stupid.

He gone!

Lmao great post ! But really the m156 is a beast N/A when properly uncorked ! Really the only engine that can compare is the ls7 and other exotics for straight out N/A power. The s65 was a great motor for Motorsport but for the street the m156 takes the cake. Great throttle response, big torque everywhere, high redline for a big displacement motor and that sound !!

I'm sure AMG will get this motor sounding right though can't be better then a n/a 11.3 compression v8. Power wise potential from bolt ons will most likely destroy the m156 we've seen what the 2.0 has done in the 45 with 400 hp with a stage 1 piggyback. If they use the same range of turbos this thing will be an absolute monster combined with lighter weight and a better chassis don't be surprised if this thing is considerably faster in everyway then the w204 c63. It's evolution it's supposed to get better from what they've learned in the 7+ years since it's been released. I wasn't considering this as a next car but the rwd announcement put it back in the running. I wouldn't mind if they kept the MCT as long as they figure out that stupid paddle delay. We shall see once everything is official and tested all speculation until then but it looks good

Precisely.............that's kinda what I've noticed with the numbers. At some point MB decided to let the 63 be more an indication of the power levels than actual displacement.

Of course, to that some might say what about the supercharged 5.5s from the early/mid 2000s E55s, for instance, that the 63 replaced? It had similar numbers. Again, the thought process evolved.

And while we're on the topic of the M156 and AMG 63s' nomenclature, uh, short of gas mileage numbers that don't live up to today's CAFE standards.............was it really that bad to put 'em in all AMGs? Considering it can upgraded to M159 SLS levels, that is, around 620 hp/480 lb.ft.? Bring it on, dawg.

Also, considering that it was International Performance Engine of the Year in 2009 and 2010, only to be replaced by a Ferrari V8 (2011) and the Berlinetta's V12 (2012)? Answer me that.

I say we stop being dumbasses, start drilling for more of our own frickin crude, drop gas prices back to January 2009 levels ($1.80 - $1.90) or less, and bring back the damn M156 and M159. Not that $3.50-4.00 a gallon ever scared me; spent too many years in Europe, so wake me when it hits $10/gallon. (About $5 after most of my fellow Americans will $#@!in & moanin, thereby dropping prices right back down. Hah!)

But I digress. Back to the M156.

It is the world's and my favorite DTM engine for the street, but way more nasty @ 6.2 liters vs. 4.0 limited displacement in the DTM. Can't wait to drive it later today. I mean, come on.............370 lb.-ft. @ 2000 rpm? Just over 400 @ 3000? Yo, it idles @ 900-950!! Nasty beast.

Last, but not least, on the new 4.0? My preference is clearly the 6.3, but if the 4.0 (or 5.5 for that matter) sounds right.....like "propa" AMG V8, pulls way way harder, yet can extract even more power and gets better gas mileage?

I'll get over it. Might be crazy, but I ain't stupid.

He gone!

I hate to break it to you but the DTM 4.0 liter V8 has nothing in common with the M156 street motor other than being a V8. DTM is German Nascar.